Field of the Invention
The present disclosure relates to at least one light source apparatus capable of outputting light having a variable spectral bandwidth, at least one information acquisition apparatus including the same and one or more methods for using the same.
Description of the Related Art
There is a known system for acquiring a tomogram of a subject, called optical coherent tomography (OCT). The OCT system is used for inspecting industrial products, medical diagnosis, and so on because it is nondestructive and noninvasive.
A known method of the OCT system is spectral domain (SD)-OCT that emits light having a broad spectral bandwidth to a subject, and divides light interfering in an OCT optical system with a spectroscope to obtain spectral information. With the SD-OCT, the resolution of the tomogram increases as the spectral bandwidth increases, which requires developing a light source apparatus capable of outputting light having a broad spectral bandwidth.
Furthermore, information on substances included in a subject can be obtained by irradiating the subject with light and detecting one of light scattered by the subject, light passing through the subject, and light generated from the subject. For example, fluorescence imaging is known in the field of biotechnology, in which light with a specific wavelength is applied to a subject marked with a fluorescent dye to cause the subject to emit light, and the distribution of biological substances included in the subject is observed. In such fluorescence imaging, the wavelength of illumination light may be matched with a fluorescent dye absorption wavelength. This requires a light source apparatus capable of outputting light having a center wavelength close to a fluorescent dye absorption wavelength and having a narrow spectral bandwidth. Furthermore, various kinds of fluorescent dye having different absorption wavelengths are used depending on the biological substance observed. This requires a light source apparatus capable of outputting light with a variable center wavelength.
R. Andrew Wall et al., “Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope”, Journal of Biomedical Optics 17(8), 086003, August, 2012 discloses a multi-modality apparatus in which SD-OCT that emits light with a broad spectral bandwidth and fluorescence imaging that emits a narrow spectral bandwidth are combined.
To emit light with a broad spectral bandwidth and light with a narrow spectral bandwidth to a subject, the multi-modality apparatus disclosed in Journal of Biomedical Optics 17(8), 086003, August, 2012 is equipped with a light source apparatus including two optical systems (light source units) having different characteristics and switches between the optical systems for measurement depending on the modality. This disadvantageously increases the size and cost of the apparatus.